Valid 010100Z – 011200Z
…THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN
PENNSYLVANIA TO NORTHERN NORTH CAROLINA…
…SUMMARY…
A band/line of strong to severe thunderstorms will continue
advancing steadily eastward this evening. Scattered to widespread
damaging winds and a few tornadoes are expected.
…01z Update…
Well-defined short-wave trough is progressing across the OH Valley
with strong large-scale forcing for ascent now spreading across
upstate NY – PA – northern VA. Mature squall line, with embedded
bow-type structures, has evolved along the advancing front. This
activity is surging east at roughly 30kt and should approach the
Middle Atlantic Coast over the next few hours. 00z soundings ahead
of the squall line exhibit very poor lapse rates with minimal
buoyancy, though roughly 700 J/kg MUCAPE was noted at IAD this
evening. Of particular concern is the observed wind fields. 50-60kt
southerly flow is noted just off the surface, within 1km AGL. Shear
profiles remain favorable for sustained organized squall line
capable of embedded circulations. Damaging winds are the primary
threat with this convection, though a few tornadoes are possible
with the strongest updrafts along the line.
..Darrow.. 11/01/2019
$$